When buying a laptop computer there are three common feature

When buying a laptop computer there are three common features that are often considered by buyers: A) tablet screen, B) backlit keyboard, C) CD/DVD drive. 25% of the purchasers request a tablet screen (A), 50% request a backlit keyboard (B), 85% request CD/DVD drive (C), 90% request a tablet screen (A) or a CD/DVD drive (C) or both, 95% request one or more of these three features, Interestingly no one has ever wanted a tablet screen A and a backlit keyboard B. What is the probability that a buyer who has already chosen a tablet also chooses a CD/DVD drive?

80%

32.34%

21.25%

60%

Solution

What is the probability that a buyer who has already chosen a tablet also chooses a CD/DVD drive?

probability = (1-0.85) / 0.25 = 0.6 = 60%